What you are trying to do is possible to do, but it requires a bit off work and know-how from you, the developer. Input field as you might know from QlikView is not implement into Qlik Sense as and Qlik offer no alternative pre build solution for it in Qlik Sense.
Qlik Sense is created on a modern web technology and offers a bunch of APIs for as system interaction. To accomplish what you're trying to do you will have to create your own web service that is taking care of your input values and use the Qlik Sense APIs to interact between your webservice and Qlik Sense.
There might be companies offering a pre build solution for your need or it might be open source projects, that your can take part of, available to help you get started. I would recommend you to do a search in the Qlik Branch Garden for available projects.
Good luck in finding a solution for your business need.
Vegar
