The phrase "to select another contact" means choosing or picking someone else from a list of options to communicate with or connect to. Full definition
To start up a secure conversation, tap the floating action button in the bottom - right corner, then select a contact from the list. (android.gadgethacks.com)
Share tasks with selected contacts or with the world. (lawsitesblog.com)
The app uses the audio pairing to detect the nearby users and we have to manually select the contact for making the payment. (phoneradar.com)