"both the users" or "the both users"?

"The both users" is incorrect. The determiner both has already qualified users, so you know who is being referred to. (Refer also to this excellent answer on ELL.) Adding the onto that is similar to saying "the the users". People sometimes do this anyway, such as in the phrase "the both of them", but it's informal.

On the other hand, "both the users" is short for "both of the users". The of is just elided. I would think this is common enough to be acceptable. But if you're in doubt, either use "both of the users" or, as MikeVaughan suggests, "both users".

I think that the article the is extraneous.

It can be seen that both users are able to...

is just fine.