There are a few good threads on this over at tank-net.org
You might want to check out the revised 1989 NATO order of battle which contains the orbat of the German army including the Territorial army. Its up to version 8 now.
http://208.84.116.223/forums/index.p...c=20414&st=680
direct link to the NATO order of battle
http://www.microarmormayhem.com/NATO...TTLE_mod_8.doc
its very thorough.
German Territorial army is similar to the National Guard or Reserves and was under German command. Separate units, not necessarily to round out or reinforce the Bundeswher or active army. A few Territorial army units worked very closely with active army units, for example one of the Heimatshutz regiments worked very closely with 6th Panzergrenadier Division.
Here is a link to the thread on the Bundeswher orbat circa 1989, lots of detail, most of the info has been incorporated in the NATO order of battle mentioned above.
http://208.84.116.223/forums/index.p...c=24760&st=700
In the Bundeswher thread, one of the contributors also complied all the information into a pdf. Its in German, but you can get the idea.
http://www.microarmormayhem.com/BW_Territorials.pdf