It was John W. Warner who was center stage here after the short pro-forma ritual that gave him the Republican senatorial nomination, but it was Joel T. Broyhill who seemed most at ease, turning former strangers into future friends, buttressing the candidate's ambition with his own expertise.

Joel T. Broyhill was back.

At times, at the John Marshall Hotel, it seemed he was everywhere - gallantly escorting Elizabeth Taylor while her husband waited for his nomination to be secured, standing at the candidate's right hand in the reception line, flashing smiles at old allies and pumping the flesh of new ones, gliding effortlessly through the first rites of Warner's second chance.

It has been nearly four years since Broyhill lost the perks of power and a shot at being the ranking Republican on the House Ways and Means Committee to Joseph L. Fisher, a mild-mannered economist in the angry reaction that followed Watergate.

Now Broyhill - the man who dominated Northern Virginia Republican politics for 22 years - is stepping back into the spotlight as if it were the warm and welcome glow from the family hearth.

"After 22 years in the limelight, I thought it would be presumptuous of me to be very visible at first," Broyhill said. "I wanted to be subdued for awhile. I thought it would be better tactically."

"Well," he said, "I've been subdued long enough."

Broyhill has not been a total stranger to his parties political fortunes in Virginia the last few years, but, until recently, he has taken a discreet, backstage approach to the candidates and their contests.

Two years ago, he campaigned for State Delegate Vincent F. Callahan, then a candidate for the seat Fisher took from Broyhill in 1974. Last year, Broyhill contributed time, money and the use of a twin-engine airplane to Governor John N. Dalton, then campaigning for the office he went on to win.

And this year it has been John Warner.

Shortly after Warner officially acknowledged last winter what had been obvious for months - that he wanted to fill the seat Sen. William L. Scott (R-Va.) was leaving - Broyhill passed the word through a circle of mutual friends that he was interested in being active in Warner's campaign, according to a former Warner campaign aide.

Broyhill promptly was named Warner's campaign chairman. His interest made him the first and, for a time, the only established Virginia Republican in the Warner camp, a following composed, for the most part, of newcomers to the state's Republican politics.

The value of that particular piece of political currency was clear in terms of Warner's chances for the nomination long before the state convention June 3.

Despite the fact that Broyhill has held no political office or position of power within the party structure for the last four years, he, observers any, has maintained his knowledge of and experience with party power brokers throughout the state, an invaluable asset to a political neophyte.

Virginia Lampe, a member of the Republican state central committee from Arlington, points to a Broyhill-sponsored open house at Dalton's inauguration last January as an example of the ex-congressman's importance to Warner.

"He (Broyhill) has always been a statewide power," she said. "His open house was at least as full as the ones given by members of the congressional delegation." And it was there, Lampe said, that Broyhill took the opportunity to begin introducing Warner to "the regular party contacts that are so important to a candidate."

Warner "didn't have a political base here that established his philosophy," Broyhill said. "I could vouch for the sincerity of his beliefs. I'm deeply flattered that some people are behind John because of my support for him."

What Broyhill gets out of this alliance is less obvious. "Whatever he gets out of it," said one veteran Republican, "he's probably going to have a good time at it. We're always liked being a power wielder."

Broyhill himself is not sure what his official role in the fall campaign will be although at this point he is less concerned with form than content. "There's already so many people who want to play a prominent role in his campaign," Broyhill said, "that I don't know what the official title will be."

Whatever the future of their relationship, the length of their acquaintance is already being used to reinforce Warner's somewhat tenuous ties to the state he seeks to represent. "Why, John's always been part of the group," said Stanford Parris, who represented northern Virginia's Eighth District when Broyhill represented the Tenth and was defeated in the same year. "We've known him since his undersecretary of the Navy days. It's a pretty closed little fraternity."

After all, Parris said, "he (Warner) didn't come out of nowhere like Robert Kennedy in New York."