Time Machine's GUI is great for your applications' documents; but, when you want to restore files that require superuser privileges, you need the extra control you get from OS X's tmutil command.

sudo tmutil listbackups shows you which snapshots are available to restore from:

...
/Volumes/.../2014-08-30-014922
/Volumes/.../2014-08-31-002302
/Volumes/.../2014-09-01-022453
/Volumes/.../2014-09-02-015445
/Volumes/.../2014-09-03-020003
/Volumes/.../2014-09-04-002614
/Volumes/.../2014-09-05-023820
/Volumes/.../2014-09-06-020504
/Volumes/.../2014-09-07-014641
/Volumes/.../2014-09-08-001751
/Volumes/.../2014-09-09-003142
/Volumes/.../2014-09-10-005409
/Volumes/.../2014-09-10-094443
/Volumes/.../2014-09-10-115715
/Volumes/.../2014-09-10-141342
/Volumes/.../2014-09-10-162715
/Volumes/.../2014-09-10-183949
/Volumes/.../2014-09-10-205256
/Volumes/.../2014-09-10-230350
/Volumes/.../2014-09-11-011645
/Volumes/.../2014-09-11-032854
/Volumes/.../2014-09-11-054003
/Volumes/.../2014-09-11-075156

Then you can use grep and mdfind etc. to locate the files you want in the particular snapshot you want.

Finally, you use tmutil restore:

tmutil help restore