do as you wish really. The path is from your q3ut4 folder. So think you are in your q3ut4 folder where is it?
So i go "models" then to a folder i have made for all my models called "dagf" then to this models texture and mode files, and they are in the folder called "btf".
The full path is "C:\ut4mapping\q3ut4\models\dagf\btf\"
the path to the texture is "models/dagf/btf/".
I hope it was possible to understand?