Using 'OR' in a issue filter

Is there a way to create a filter than allows you to basically use an 'or' rather than 'and' for its results?

For example, I have a custom query that gives me all issues assigned to me (status = open and assigned = me). It would be nice to also show items that I watch, which would be more like (status = open and (assigned = me) or (watched by = me)).

You can do something like this on the 'My Page' page, but I want to see everything as a list of issues.