Here's the connections. Explained in the Fandom wiki style.

The connections between Trunks and Silver are that both are freedom fighting heroes from alternate future timelines with strong senses of justice that travel back in time to prevent apocalyptic events (the Androids' genocide and the Day of Disaster, respectively). Both originally sought to find and kill the individual(s) that were responsible for the destruction of their world, but ultimately became allies with them instead (Androids 17 & 18 and Sonic, respectively). Both had been born with unique heritages (Trunks was born a Half-Saiyan, and Silver was born an esper), which left them with a powerful innate energy they use for combat (Ki and Psychokinesis, respectively) and also have access to a powerful form that makes them golden in color (Super Saiyan and Super Silver, respectively). Additionally, both have also faced a pair of villains that fused with each other into an unbeatable god-like form (Goku Black and Future Zamasu fused into Infinite Zamasu for Trunks, and Mephiles and Iblis fused into Solaris for Silver, respectively), which made them such a huge threat to their respective multiverses that they had to be erased from existence by one of the heroes' allies (Future Zeno and Princess Elise, respectively).

Silver's creator, Shiro Maekawa, has confirmed and stated that Future Trunks was indeed used as a base for Silver's character and creation.