You may follow the guides below to select multiple channels/cameras when live-viewing on Reolink App. 

Applies to: All Reolink cameras and NVRs.

Step 1. Go to the live-view page and tap the three_dots.pngicon on the top right corner to show the drop-down menu.
Step 2. Tap Channel Selection.

tap_channel_selection.jpg
Step 3. Select the cameras or the NVR channels you want to view. Tap Done on the top right. 

choose_the_channel.jpg

Step 4. Select the number of screens you want to display. 

tap_split_view.jpg

Done! You can see multiple cameras on one screen at the same time now. 

multiple_views.jpg

Channel selection working mechanism: Unchecking a certain camera or a certain channel under NVR in channel selection will affect the immersive and normal live view of the camera (that is, tap the camera on the device list/main menu page to live view directly). If you want to live view this camera, you can directly tap the camera on the device list/main menu page, the camera will be automatically re-checked in the channel selection.

Note: Once more than 1 channel or camera is selected, the Multi-screen Options will be enabled, which allows you to live-view multiple devices via Reolink App. You may refer to How to Live View Multiple Cameras via Reolink App