Sí, es ése, fp. Al acotar tu búsqueda la delimitas, haces que sea más selectiva, vas más a lo específico. Me quedo con "refine".I haven't heard or seen "acotar tu búsqueda", but the dictionary tells me that 'acotar' means "to delimit". If you were starting with a delimited search, then you could probably say "do a bounded search" as chics suggested -- although I haven't heard that term before.
However, "refine your search" is very standard Internet terminology, and it applies to any search that you perform whose results are too broad. The search site or program will ask you if you want to narrow or refine your search. Is that the sense of "acotar"?