The first step is to click on the "Edit filters" button (option 2 in the first image in this tutorial).
A large right sidebar will automatically open.

How To Add Filters in Dynamics 365 Personal View

In our case, the 'All Contacts' view has no additional filters applied, and the sidebar also contains no filters.

Now, let's create a filter to help you locate Contacts with Alex as their first name.

To do so, open the +Add dropdown (3) and select the "Add row" option.

In the dropdown, you can also find the "Add group" option, which is helpful for creating OR/AND conditions, and the "Add related entity" option, which is required to create conditions based on related entity data.

How To Add Filters in Dynamics 365 Personal View

After that, you will get an empty filter template.

The first field needs to be selected, the second needs to select the operator (equals, contains data, etc.), and the final field needs to contain the data we are looking for.

In our example, we need to find a Contact whose name starts with Alex, so our first filter should look like this:

How To Add Filters in Dynamics 365 Personal View

Now let's add a second filter for the Company Name that should contain "Re" as a part of it:

How To Add Filters in Dynamics 365 Personal View

The third filter you need is the one about the Mobile Phone field that ends with 0129.
After that final filter is added, click the 'Apply' button (5) at the bottom right corner.

How To Add Filters in Dynamics 365 Personal View

As a result, you will get your mysterious Contact record.
Please note that the Mobile Phone column is not present in this view, so do not mistake it for the present Business Phone column.

How To Add Filters in Dynamics 365 Personal View

If you need to adjust current filters, just click on the "Edit filters" option again, and all your filters will be displayed.

I need to mention that different types of fields have different Operators available. As an experiment, add the CreatedOn field to the filter and check the available Operator options.

That's it!