Here are some of the best G-mount lenses to pair with it:

Standard Zoom

• Fujifilm GF 32-64mm f/4 R LM WR - A versatile standard zoom covering wide to short telephoto focal lengths. Sharp optics and weather-resistant build.

Wide-Angle

• Fujifilm GF 23mm f/4 R LM WR - A high-quality wide-angle prime lens. Great for landscapes, architecture and environmental portraits.
• Fujifilm GF 30mm f/3.5 R WR - Lightweight and compact wide-angle lens. Ideal for street photography and travel.

Portrait

• Fujifilm GF 110mm f/2 R LM WR - A stellar short telephoto prime for portraits. Extremely sharp with beautiful bokeh and weather-sealing.
• Fujifilm GF 80mm f/1.7 R WR - The fastest G-mount lens available. Perfect for low-light shooting and shallow depth-of-field portraits.

Macro

• Fujifilm GF 120mm f/4 Macro R LM OIS WR - A 1:2 macro lens with image stabilization. Also works well as a short telephoto for portraits and still life.

The ideal lens choices depend on your preferred shooting style and subject matter. But you can't go wrong with any of Fuji's high-quality G-mount glass. The GF lenses deliver exceptional sharpness, color rendering and build quality to take full advantage of the GFX 100S II's 102 MP sensor.

I use GF 32-64mm f/4 R LM WR for the most time for my GFX100S, a great lens.

Based on what are shooting, you can find suitable lenses at B&H.