With reference to the below posts

Sorry. AFAIK import is not supported or easily possible. Technically, when you export an Appian process model it becomes a XML file. So you could create such a XML file and import it. My experience is that a process model in Appian look so much different then a model you would use for documentation that, at the end of the day, this approach takes more time to develop.

Thank you Stefan for the reply, I have already have this point but wanted to hear from anyone who have attempted to this. Our main Intention is as follows,
Lets say we have a flow in PEGA and Now it is a very complex flow we have the XML of it and Now we have a sample XML of Appian. My Question is
What are the points or the ways to be considered to change the XML format of Pega to the Format and Tags of Appian. Rather designing in the front end we wanted to know what are all the possible ways to change the xml of any BPMN tool to XML of Appian. I saw Malcom ross pointing about this in one of the posts mentioned, It would be great help for us if he provides any comments on this post .Thanks in advance !!!

Not sure if I can add the participants into this post, but added Malcolm ross into the participants , welcome sir :)