The Epic represent a huge business requirement. Sometimes business requirements are too big to be completed in a single project. For example an epic,

building a portal which could support billion of users at a time
, may take several projects to complete it. Therefore Yodiz allow to have Epics span across multiple projects. But there are times when you might want to restrict an epic to single project. In that case an option of limiting an epic only to a specific project is available in Yodiz. A check box
Add in Current Project
limits an epic to the current project.