PHP dynamically create multidimensional array keys

I need to dynamically compute my multidimensional array keys for an aggegration in Elasticsearch.

I have the following

$aggs['aggs']['name']

But aggs and name needs to be populated in a loop. So for example:

 $aggs['aggs']['name']['aggs']  = $glue;

// looping

$aggs['aggs']['name']['aggs']['name']['aggs'] = $glue;

// looping

 $aggs['aggs']['name']['aggs']['name']['aggs']['name']['aggs']  = $glue;

// etc

The array keys needs to be computed with the keys aggs and name

How can i dynamically create keys in an array?

Thanks