When adding a decision in a process flow, promapp doesn't allow to add more than 1 activity (sometimes, what you need is just 2 or 3 activities, not another process) on a YES or NO outcome.
The CONTINUE option just lets you continue with the rest of the process flow.
Its not ideal to create another process with 2-3 activities as the activities are part of the current process based on a YES/NO outcome.
Hope Promapp fixes this soon.