php-about embedding a loop loop statement in an HTM file

Phploophtm Cycle

I am now going to do a section of the Authority control page. First I wrote a few arrays in the PHP file, there is a level department, level two department, level three department. These three departments are subordinate. For example, the first-level department is a one-dimensional array, the level two department is a two-dimensional array, and the three department is three-dimensional array. In the HTM file I want to loop the display with loops. In the third level of each Add checkbox, select Submit after the PHP file processing. The problem now is that it's not clear how the loop loop is written. I found the following wording:

   
                                                       
                                  checked="true"                              
     
                                     >                               $regular[name]                                                   
   
   

I just need that $regular "name" and change it to my own name. What should I write about the department array? and is the loop loop inside the HTM language? Or is it embedded in other languages?
In this respect, what should I look at?

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