@Angelitos could you outline the steps you did here: “i have tried to tag them by filter them first by orders but when i am trying to choose the customers with the tag i cant find them .”
It sounds like you tagged the customers but cannot filter them by tags, so you might have just missed a step, or need to save the tags or refresh the page.
For example, if you filter customers in the Customers section in Shopify, then add tags in bulk, then click Save, those customers will now have that tag.
Now you can easily filter those customers by selecting the “Tagged with” dropdown then export those tagged customers however you’d like.
If you want to avoid manually tagging customers, Order Automator can automatically tag all past and future customers according to what they order.
If you’re wanting automated emails sent out, Avada’s solution sounds like it would work (I haven’t used their app but I’ve used a few ecommerce email marketing softwares and this is a common workflow, cross selling provides a nice automated revenue stream).