Shantae Dance Matching
JavaScript (ES6),  92 88 61  59 bytes
Saved 2 bytes thanks to a suggestion from @tsh
Expects UdLRAB for the dance moves and . for waiting. Outputs either undefined if there's no match, or the sequence of the matching dance (e.g. dR for Monkey or dURLAB for Water Town).

s=&gt;(/d([A-R]|U(U|A|LR|RLAB|RRBA|LLBA|BLBR))/.exec(s)||0)[0]

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