Click on 'New skill matrix'. Then choose how do you want to do it: "With a template" or "From scratch".
Let's create a skill matrix from scratch. Type the name of a skillboard. 
To add a skill group, press "+" and type the name of the skill group. 
To add the skill to the skill group, press "+" and type the name of the skill. 
This is how a skil matrix is created. To complete the skillboard, add all skills and skill groups you need. 

Now let's create a skill matrix using a template. To do this, choose "With template" option. 
You'll see a new window. Choose a skill group and press "Apply". You can also use the search box for quick navigation.