совершавших

In a sentence

• Герои, совершавшие подвиги, вдохновляют нас.

  Heroes who committed feats inspire us.

  In this sentence, 'совершавших' is used in its participle form to indicate past actions performed by the heroes who inspire us.

• Совершавшие ошибки должны были исправляться.

  Those who made mistakes had to correct them.

  Here, 'совершавшие' functions as a plural adjective derived from a participle to describe individuals who made errors.

• Они наблюдали за группой, совершавших странные действия.

  They watched the group that was performing strange actions.

  In this context, 'совершавших' describes the group engaged in the ongoing or habitual action of performing unusual deeds.