Adding an additional settings item when adding content

The task is as follows:

There is a section for individuals, and there will be a couple of tens of thousands of them.

There is also an events section, with a practically identical number.

Individuals and events are linked; when adding an event, it is necessary to select the connection to an individual.

So, if there are a couple of tens of thousands of individuals, adding them will be extremely inconvenient, as for example, there will be many Abdulaevs, and a filter by Last Name, First Name, and Patronymic needs to be created so that when selecting Vasychkin, all Vasychkines would load.

Visually, the implementation looks something like what is shown in the screenshot.

Can you advise on where to start? What constants should be used when writing the module? Are there any other solutions to this issue?