You can do this using the OpenVideoPlayer action.
1. Open the page that has the button you want to play a video.
2. Select the Settings button in the toolbar.
Note: If the Toolbar is hidden, first select the Modify Button at the top right corner of your screen, then Settings.
3. Select Editor.
4. Select the button you want to play the video.
5. Select the Properties button at the top left corner of the button to open the Button Properties panel.
6. Add a label and symbol if necessary.
7. Select the Actions text box to open the Script Editor.
8. In the Script Editor, search for Open Video Player.
9. Select the OpenVideoPlayer action. The Select a Video File screen will open.
10. Select the File… button at the top right corner of the screen.
11. Navigate to the directory where you have saved video files.
12. Select the video you want to play in the Video Player. The Script Editor will reopen with the OpenVideoPlayer action listed.
13. Choosethe green Done button at the top right corner of the screen.
14. Select Exit on the Editing Toolbar. When a dialog opens asking you if you want to save changes to the page, select Yes.