Hi @Akhanjer,

You can use the Activity SmartObject to execute a “Go to activity” method (You will need the process instance ID):
The activity smart object can be found under System>Management>Workflows>SmartObject

In this example, i used a button to end the workflow and I passed the Process Instance ID through a textbox:

 You can get the process instance ID using the “Process instance info” in the same category and filter based on your workflow folio (assuming the folios are unique) or you can simply save the instance id when the workflow starts and retrieve it when needed based on which item it is related to. 

As a side note, I do know that this may not work for other activity calls properly (I have experienced problems with this in k2 5.4, something to do with the naming of activities) unless it has been fixed. It does work perfectly with the end activity though.

Hope this helps :)