Complex sentence: In Poland, there was the main show its two spin-offs also on the Polsat network, "Hugo Family" and "Hugo Express", where it remained the most popular children's program for years.
Split into simpler sentences: In Poland, there was the main show, and its two spin-offs, all of which were shown on the Polsat network. The spinoffs, "Hugo Family" and "Hugo Express", were the most popular children's programs for years.