TMary Tyler Moore's new CBS variety hour, "Mary," premiering Sunday night at 8 on Channel 9, is a claustrophobically inner-directed entertainment in which most of the reference points have something to do with show business. It reflects the tunnel-thought of people who are out of touch of the America that lies beyond L.A.

However, the Mary Tyler Moore show is the only new program on TV that stars Mary Tyler Moore. That is a considerable distinction, and a crowd of predominantly likable supporting players also helps give the program a sunny disposition and welcome charm. It just has to broaden by a wide shot its comic scope.

At some point, spoofing show-biz fatuousness becomes its own kind of fatuousness; this is what helped kill "America 2-Night," for all its fitful wit. "Mary" is produced and its writing supervised by Tom Patchett and Jay Tarses who also did "The Bob Newhart Show" for MTM and they seem to think they are doing a situation comedy about a former sitcom star who now has her own variety show.

Naturally one expects some introductory material on a new show, but "Mary" is mired in self-appraisal and the in-joking of people who have run out of ideas on what to do with television. When Carl Reiner shows up 25 minutes into "Mary" to review "the first 25 minutes of 'Mary,'" you can see the satiric point being made, but too much of the show scores wee zingers from the same source.

Of the show's stock company, veteran Dick Shawn is by far the Supreme nectarine, though he is given almost nothing to do on the premiere. Time has given Shawn the appearance of a demented Gepetto; there is something about him that suggests compulsive fiendish mischief.

More-or-less newcomers include the attractive Swoosie Kurtz - who needs better material than dull jokes about her odd name - Judy Kahan, also one of the show's writers, and Michael Keaton, themost comically promising of the younger players.

And then there is James Hampton, a prankless pankster who not only looks like Bob Barker but proves less amusing. Dozens of irritating commercials in which he has appeared make Hampton's presence on this program an automatic intrusion.

"Mary" does not follow in the rolicking footsteps of Carol Burnett; its comedy is too tame and low-key. You never get the feeling that the members of the cast are having the romp they feign, and the fact that it is taped in modular units, not straight-through, shows in a lack of cohesion. The sum effect is of a television program sitting on its hands in front of a mirrow - show biz self-indulgence and creative catatonia.