I don't think it's wrong but DL is not programed to accept it. Things are pretty literal around DL and there are some quirks, some laughs and a good foundation in languages. If you were still at the site you could have reported it.
I humbly disagree with christian. If you want to use "dieser" for both then you have to add hier (here) or dort (there) to distinguish. This = dieser hier, that = dieser dort. But there is a word which directly equals that: jener