How to use last parameter (term) as a filter in a view
Yes, you can add a separate block with the same settings and in the contextual filter get form from the url.

Add the blocks in the same region and in the visibility settings select Only the listed pages and add docs/*/* for child terms and to the other block add docs/* for the parent terms.

UPDATED:

If you have a Taxonomy type page view then you can do the following thing.



Create tow pages with path as docs/* for parent terms and docs// for child terms i.e. form.

In the contextual filter add term id and select This Page override. and check Provide default value. In the Type drop-down select Raw value from URL and then from Path select 3 for docs/%/% path and 2 for docs/% path.