GNU/Linux Mint 19 Installing Broadcom Bluetooth Driver Guide
How to Install Broadcom Wi-fi/Bluetooth Driver on GNU/Linux Mint 19.x Tara/Tessa/Tina/Tricia LTS desktop – Step by step Tutorial.
And to Setup Broadcom Bluetooth Interface on Linux Mint 19 it’s enough to Install the Broadcom Wireless Driver.

Installing Broadcom Bluetooth Driver on Linux Mint 19