Your left sidebar is probably auto-hiding. Make sure MB is full screen, then move your mouse cursor until it runs into the left edge of the screen and leave it there until your left sidebar expands. There will be a pin icon at the top right of the sidebar when it appears if you'd like to keep it visible at all times.
If you don't see Computer listed in the left sidebar, make sure it's selected in the preferences:
Ctrl+o > Layout (1) > Make sure Computer is selected in the Left Sidebar section.
Home Desk ~ MB 3.3 Portable • Questyle CMA400i (ASIO) • Sennheiser HD 660S (balanced) / Audeze EL-8 Closed Back / Fostex TR-X00 Ebony • Teac AI-101DA • Jamo C93 + Dayton Audio SUB-1000
Work Desk ~ MB 3.3 Portable / Tidal • SMSL SU-8 v2 • Nobsound NS-05P • THX AAA 789 • Sennheiser HD 58X (balanced)
OTG ~ FiiO M11 • Audiofly AF180 / B&O H6