Schaf
2022-04-27T10:31:32Z

As far as i figured out, you can't.

In Fedilab any reply is put on top of your timeline. By tapping on one of these, you open the thread belonging to this reply.

In Tusky it seems a litte bit better, because the timeline only shows up the posts of these accounts, you are following.
But as soon as there is a new reply to one of these posts, itself is shown on top of your timeline, regardless how old it is. Again by tapping on this post yout get the wohle thread of replies.

There is a setting in "social networks" > "general social media setting" called "Followed content scope", which doesn't affect the behaviour of these apps.

There ist a litte bit outdated app called DiCa, which does what you are looking for.