You can search entries by multiple category tags by selecting + to include a tag and - to exclude a tag.
You can use the drop-down Namespace menu to limit searches to entries in either the audiodrama or roleplaying directories. (Other namespace directories are older ones that are in the process of being phased out.)
Select Use logic AND to refine searches to include a combination of your selections, otherwise the search will return all entries with every included tag that you selected.