By default, the series are listed alphabetically and you can go directly to a known variable by clicking the first letter of its name or searching. However, there are over 1300 variables here and you might want to explore before committing. Use the filter button to view the series by meaningful category.
For example, if I select “Growth rates” from the filter, my options drop to 17, which I can easily browse.

Each series has a small "i" in a circle, which provides definitional information about that series such as what is included and excluded, base years for indexes, units, and original sources for the data. This information is often essential for making an informed decision about which series to use. Later, at the download stage, you can make sure you bring this information down with the values for consulting later in your process.

Again, your selections will show in the grey rectangles.

Now, you just need to say what years you need. Move on to the Years dimension.