The story of some of these is actually pretty funny

So basically in 2017 the Communist Party of Nepal (Maoist Centre) and the Communist Party of Nepal (Unified Marxist-Leninist) together won the elections by a landslide, and a year later in 2018 they decided to merge their parties into one party called the Nepal Communist Party, so they did that and merged. However, in 2021 the Supreme Court decided the merger was invalid because the name was already taken by a different party, so they split back into the two original parties. But that's not all, right after the Nepal Communist Party split back into the Communist Party of Nepal (Maoist Centre) and the Communist Party of Nepal (Unified Marxist-Leninist), the Communist Party of Nepal (Unified Marxist-Leninist) had some infighting and so some people decided to split off and form a third party, the Communist Party of Nepal (Unified Socialist).

Edit: Oh I almost forgot, a fourth party showed up in 2022 when the Communist Party of Nepal (Unity National Campaign) also split from the Communist Party of Nepal (Unified Marxist-Leninist)