Custom Segments are your friend here. Create a new custom segment that will limit users or sessions to those who have triggered any one of the events you want to include in your report.
In Analytics, click the Segment (it'll typically say, All Users) and click the red + New Segment button. You'll need an advanced segment, select either sessions or users depending on which you'd prefer. Then include dimensions relevant to the events you want. You can filter by Event Category, Action, or Label and you can chain several filters through AND/OR options.
Do be aware when using segments that Analytics will tend to default to the last one used, so if you're not familiar with using them get into the habit of double-checking which segment is active when reviewing data and especially when generating reports.
This is the only way to filter the flow reports (both Behaviour Flow and Event Flow) as there are no other filter options for these reports.