Political parties typically do, and some are known to use Telegram for their internal groups. Any leakage of secret knowledge shared only through these groups

Political parties typically do, and some are known to use Telegram for their internal groups. Any leakage of secret knowledge shared only through these groups could be detected as treason by one of the participants in that channel. Having several channels with fewer and fewer members, closer to the party's leadership, is a typical configuration to maintain control of the most secret information.