You can experiment a bit with this explorer. An extensive help file can be found here.
In brief, you can do this as follows:
In the first tab, you select the criteria ‘Mathematics and Science’ and ‘Grade 4’.
In the second tab, you choose the variables you want to look at: the ‘measure’ is ‘TIMSS Mathematics Scales: Overall Mathematics details’, choose your report years, and countries.
You construct reports by choosing what you want in the reports. Choose your own country or a country of your choice for your report. You can build multiple reports.
You then edit the report.
Finally, you build the report.
You can do quite a lot of complex analyses with the explorer. Have a look at the TIMSS 2015 Grade 4 results for your country.