Q: Connecting Thunderbolt to Display AND for Ethernet

Hi Everyone. I wonder if I could tap into your collective wisdom please?

I have a MacBook Air with a single Thunderbolt connection. I use this to connect to my office internet via a Gigabit Ethernet Adapter/cable.

However, I also need to connect my MacBook Air to an external (larger) Display. This also needs to use the same Thunderbolt connection (for a Thunderbolt to HDMI cable).

I have searched the Apple store and various online stores, but I can't seem to find any adaptors that allow the single Thunderbolt connection on my MacBook Air to connect with both the Ethernet cable AND to an external display.

Does anyone know if such an adapter exists please? And if not, does anyone have any advice on how I can get both the Ethernet and Display to work in parallel?

Thanks in advance.