If you're looking for general subject headings in the library catalog, the following might be useful for the social sciences in general:
However, research methods are varied & interdisciplinary so researchers from different fields describe them in all kinds of ways. For example, in addition to “community-based participatory research” (CBPR), you’ll also find the keywords below in use. You don't have to use all of them but thinking about different keywords can help you expand your search and locate the subject headings that the databases you're searching use. Then add these terms to the specifics of the topic you are searching or the community OR region.
“community-based participatory research” OR CBPR OR “participatory action research” OR “participatory research” OR “community-based research” OR "community engaged research" OR “community action research” OR “collaborative action research” OR “action inquiry” OR “action science” OR "emancipatory action research" OR “community partnered participatory research” OR “mutual inquiry” OR “collaborative inquiry” OR "cooperative inquiry" OR co-production OR “citizen participation” OR “citizen science” OR participant observation OR “community involvement” OR “cooperative behavior” OR “community-institutional relations” OR “community-based participatory action” OR “participatory evaluation” OR “empowerment evaluation” OR "grassroots research" OR $METHOD (like photovoice)