6 classes are annotated with ActivityEntityCondition in Open Social 8.8

CommentAllActivityEntityCondition in modules/custom/activity_basics/src/Plugin/ActivityEntityCondition/CommentAllActivityEntityCondition.php

Provides a 'CommentReply' activity condition.

CommentNotReplyActivityEntityCondition in modules/custom/activity_basics/src/Plugin/ActivityEntityCondition/CommentNotReplyActivityEntityCondition.php

Provides a 'CommentNotReply' activity condition.

CommentReplyActivityEntityCondition in modules/custom/activity_basics/src/Plugin/ActivityEntityCondition/CommentReplyActivityEntityCondition.php

Provides a 'CommentReply' activity condition.

MentionCommentActivityEntityCondition in modules/social_features/social_mentions/src/Plugin/ActivityEntityCondition/MentionCommentActivityEntityCondition.php

Provides a 'MentionsComment' activity condition.

MentionPostActivityEntityCondition in modules/social_features/social_mentions/src/Plugin/ActivityEntityCondition/MentionPostActivityEntityCondition.php

Provides a 'MentionPost' activity condition.

QueueStorageEntitySendActivityCondition in modules/custom/social_queue_storage/src/Plugin/ActivityEntityCondition/QueueStorageEntitySendActivityCondition.php

Provides a 'QueueStorageEntitySendActivityAction` activity action.