Check out this docking station: Lenovo USB-C Dock (2nd gen.). 3 screens are possible (keyboard and mouse anyway, you can connect them directly to the Yoga. Just check whether the connections are suitable for them (2xDisplayport, 1xHDMI).
The following is from the Lenovo homepage, compatibility seems to be good:
At Lenovo, they understand that modern businesses need a variety of PCs and brands to meet your business needs. That's why the Lenovo USB-C docking station is not only compatible with Lenovo laptops, but also supports laptops from HP and Dell. **; **: Disclaimer: Lenovo USB-C and Thunderbolt docking stations work with notebooks whose Type-C port supports the industry-standard USB-C legacy mode or Thunderbolt protocols. Lenovo's USB-C and Thunderbolt docking stations support additional features for most Lenovo ThinkPad notebooks, such as MAC address pass-through, WOL and mirrored power switches. However, these features may not be available for certain Lenovo notebooks or non-Lenovo notebook systems.
By the way, I can recommend the Yoga 7i. I am very satisfied with it. Only the expandability could be better, so the device as you buy it should meet your requirements. Of course, you can expand it with a docking station, but if you want a larger SSD, for example, I would recommend buying the device with a larger SSD (or consider another device, although there are few alternatives in this device class).