The API is huge but I think one can get this sort of thing using this call:
condenser_api.get_discussions_by_active
Returns a list of discussions based on active.
Query Parameters JSON
[
{
"tag": "",
"limit": 0,
"filter_tags": [],
"select_authors": [],
"select_tags": [],
"truncate_body": 0
}
]
See https://developers.hive.io/apidefinitions/#condenser_api.get_discussions_by_active
Maybe there are routines in there that gives you the tags are in the posts a particular user has been voting on. If not we would have to create a backend to do that part.