SOLMAN 7.2 (SOLDOC): Assign multiple keywords to the same document (Test cases)

Hi,

I am trying to assign multiple keyword to the test documents so that I can filter the documents through the keyword.

Right now I can only assign one keyword to the document and not more than that. I want to add keywords such as Compliance (for compliance testing), regression , UAT etc and tag a single document with two or more keyword for e.g. compliance and UAT. How do I do that?