Only You have to do is just download and install the this app to your phone.*This app is not available in GALAXY Store or Google Play Store. So you have to download it from google. (But this app is made by Samsung for Samsung devices only. So you can use it without any suspicion.)*to download, search "Download Task Changer apk" in Google.
Then your Recent Apps view will change like this Screenshot's.
By using this new Recent App view you can open any multi-window app without going back to home screen or no need to open edge panel too. Even when you are watching a video on youtube, you can open any multi-window support app without pausing the video.*video doesn't even pause at the Recent Apps it's always running on background while you are in Recent Apps.(also games)*to open an app in multi-window just touch and hold the app icon and drag it into the blue card displayed.