@Prtksxna Forgot to talk about this in our meeting today. More context for this here: T251459#6156958.
We can talk about it in our future meeting. Keeping this in your column for now.

In T253327#6166410, @Niharika wrote:

We can talk about it in our future meeting. Keeping this in your column for now.

We decided to keep fewer filters for now because of performance concerns. Keeping only the Duration and Targets filter means that the filters box could be common for both tabs, and so we can move it above the tabs. We'll keep the box open by default.

The Duration filter will reflect what was chosen in the initial Special:Investigate form and will apply to all tabs.

@Tchanders The user agents filter could be common across both tabs too. I don't recall what you had said about the performance hit because of adding a UA agent. We can decide whether or not to add it based on your advice.

@Prtksxna Moving the filters above the tabs means that the tabs will vertically "jump" moving between Preliminary Check and one of the other tabs. Is this ok?

In T253327#6190406, @dbarratt wrote:

@Prtksxna Moving the filters above the tabs means that the tabs will vertically "jump" moving between Preliminary Check and one of the other tabs. Is this ok?

Yep, we're ok with this.

Change 602519 had a related patch set uploaded (by Dbarratt; owner: Dbarratt):
[mediawiki/extensions/CheckUser@master] Move filters above tabs and add exclude targets filter to timeline tab.

https://gerrit.wikimedia.org/r/602519

Change 602519 merged by jenkins-bot:
[mediawiki/extensions/CheckUser@master] Move filters above tabs and add exclude targets filter to timeline tab.

https://gerrit.wikimedia.org/r/602519

• The same form (filters box) should be added to the Timeline tab.
• Move the filters box above the tabs
• Keep the filters box open by default

It is closed by default.

• The filters should be kept in sync across tabs: if a target is filtered out using the form on the Compare tab, the target should also be filtered out of the Timeline results, and the form on the Timeline tab should be pre-filled accordingly.

It persists across the different tabs and pagination.

I have been keeping an eye on the SQL in the logs while I perform investigations. I have not seen any problems in the SQL produced by TimelinePager (i.e. it reflects the current filters).

For a couple of investigations, I compared the output of the SQL for the TimelinePager with output from my own scripts, and got the same results.

I also did this for the Compare tab just in case of regressions (we appear to have combined some of the code which was separated between the Timeline and Compare tabs).