Conversation so far:
What was Gulbuddin Hekmatyar relations with the Taliban?
The Pakistani military had supported Hekmatyar until then in the hope of installing a Pashtun-dominated government in Kabul. By 1994, the Pakistanis began turning towards the predominantly Pashtun Taliban.
What happened after the Pakistanis shifted their aid to the Taliban?
The Taliban made rapid progress towards Kabul, making inroads into Hezb-i Islami positions.

Question: Who else colaborated with Hakmatyar?
Self-contained rewrite: Who else collaborated with Gulbuddin Hekmatyar besides the Taliban?