The posts_builder parameter of aw2.query allows us to write complex post queries. Here is a quick sample

[aw2.query posts_builder part=start]
  {
	"posts_per_page": 10,
	"post_type": "post",
	"post_status": "publish",
	"order": "DESC",
	"orderby": "date"
  }
[/aw2.query] 
[aw2.query posts_builder part=tax_query]
  {
	"taxonomy": "category",
	"field": "slug",
	"terms": "nature"
  }
[/aw2.query] 
[aw2.query posts_builder part=meta_query]
  {
	"key": "custom_value1",
	"value": "hello",
	"compare": "="
  }
[/aw2.query] 

[aw2.query posts_builder part=run set=results /]