Dear I really don't know and haven't ever heared of a tribe by the name of Mughal Pathan.
Mostly the term Pathan is used for pashtuns in (India and Pakistan) and Mughals are related to todays Mongolia, there are alot of mughals still living in Afghanistan, specially in the western areas such as Herat province where they are under "Temori" last name (adopted from Temor Lane).
Regarding the migrations of pashtuns from Afghanistan to the Punjab provice of today's Pakistan is also a common and ancient act, where even Ahmad Shah Abdali's father had migrated to Multan for bussiness purpose and there Abdali was born.
But still combining both ethnics togather would be only in a case where either a pashtun man marry a mughal woman or vise versa, and their children relate themselves to both ethnic, other than this, I haven't heard about the term neither in Afghanistan nor in Pakistan.