As the HREFLang element is for languages it makes sense you should be able to set global languages.  Many sites do not use country designators but have common languages. For example, if you use a /es version for "any" Spanish speaking countries then we can set it as "Global Spanish." You can do this by selecting the global language related to the site by scrolling down in the individual entry and choosing the global languages 


There is one additional consideration of the X-Default option where you can make a single language or country version the one that shows for any country were you have not set a language preference.  For more on this view our best practices on Setting a X-Default.  


If all of your websites are Language Only" with out any country designation you can set that in the Define Country Language Settings. 


If only some of your sites have this option  you can set it manually using the following process.  


Step 1 - Click the Edit File option for the dataset you want to make a global language.  In this case below we choose Portuguese site.  



Step 2 -  You will be taken to the data segment for the Portuguese site and once there click the pull down for "Country Language" and scroll until you find the entry for "Global Portuguese" and click that entry to select it.  

Step 3 - Click the blue up or down arrows to go to the top or bottom of the page and click "Update" to update the data set and the HREFLang element to make this equal to "PT" 

Considerations:  


1.  You may only have one data set equal to a language.   If you have a Brazilian Portuguese and a Portugal Portuguese site you should set them for their respective countries.  

2.  Note that this will be the language version shown in all of those markets that do not have their own language set.  For example, if you set the US to "en" and do not have a site for Australia it will appear in those results.