This issue is caused because you have run:

sudo chown -R admin:admin .*

We know that . indicates the current directory and .. indicates the parent directory. When you run the command with .*, it simply means that match any hidden file in the current directory (stating with .), the current directory itself (.), the parent directory (..). Simply put anything after . (* means 0 or more characters). As a result the parent directory along with all of it child directories get chown-ed to admin:admin.

Look at this test:

test$ ls -al
drwxrwxr-x 4 foo foo 4096 Jun  3 07:15 .
drwxrwxr-x 4 foo foo 4096 Jun  2 18:06 ..
drwxrwxr-x 2 foo foo 4096 Jun  3 07:15 egg
drwxrwxr-x 2 foo foo 4096 Jun  3 07:12 spam

$ sudo chown -R bar:bar spam/.*

test$ ls -al
drwxrwxr-x 4 bar  bar  4096 Jun  3 07:15 .
drwxrwxr-x 4 foo  foo  4096 Jun  2 18:06 ..
drwxrwxr-x 2 bar  bar  4096 Jun  3 07:15 egg
drwxrwxr-x 2 bar  bar  4096 Jun  3 07:12 spam

To revert back you need to chown the affected directories again.

I am not really sure what your plan was, but here are some ideas:

    To chown any directory recursively (including hidden files):

    sudo chown -R foo:foo /spam/egg/

    To chown only the files (including hidden files) inside that directory (not the directory itself):

    (shopt -s dotglob && sudo chown -R foo:foo egg/*)

    To chown only the non-hidden files (without the directory itself):

    sudo chown -R foo:foo egg/*