Witness the emergence of Lake Bell into the swelling ranks of multi-hyphenate women in the world of independent films. Joining the parade of women including Amy Seimetz, Greta Gerwig, Ava DuVernay and Brit Marling, Bell worked her way up after a string of bench-warming turns as a potential It Girl-in training — the standard rom-com supportive friend (What Happens in Vegas and No Strings Attached) or the untested co-lead (Over Her Dead Body and the HBO series How to Make It in America), but her feature debut as a writer, director and star showcases not only Bell’s assured hand in this power position, but also her ability to parlay her industry connections into a who’s who — Eva Longoria, Jeff Garlin and Cameron Diaz — of walk-ons with the cache to spice things up. Yet, it is Bell, as a vocal coach seeking to break into the hyper-competitive movie trailer voiceover business that has been dominated by her father (Fred Melamed), who is in firm command of her expanding world. In a World ambles along with light but deft humorous elements that never cross over into the broad hijinks we’ve come to expect from the big screen situational comedies that drop their wide load back-ends into the multiplexes seemingly every weekend. Opens Friday at Mariemont Theatre. (R) Grade: B