If you would like to get super smart on Google+ community management, then check out this tip!

To filter people in a community, and e.g. add them into your circles (or a Page) then:

Step 1:

Grab the URL to the Community, then...

Step 2:

Go to Circloscope and follow this process...

Use Dashboard > Community > Members to extract all members of the
desired community. Now use the Filter option in the top to filter the
results.

From there you can e.g. add people into your circles.

How to filter a private community using Circloscope