Specify document library columns when you design a form template
1. Open the form template.
2. On the Tools menu, click Form Options.
3. Click Property Promotion.
4. Do one of the following:
4a. To add a column, click Add, click the field or repeating group for which you want to create a column, and then type a name for the column in the Column name box.
Note If you select a repeating field to display data in the document library, you can define how you want to display the field in the document library by clicking a value in the Function list. You can choose whether to display the first value in the field, the last value in the field, or a count of all of the occurrences of the field or whether to merge all of the values together.
4b. To remove a column, click the column in the list, and then click Remove.
4c. To modify a column, click the column in the list, click Modify, and then make the appropriate changes.
Note: Some options for adding, removing, or modifying columns are available only when you publish to a SharePoint site.
Once your form is published to a desired document library, you will now need to add your infopath form fields as columns in your document library. This can be achieved by accessing the form / document library’s settings and adding the appropriate columns from the list of choices given.
If you can’t see your field, something has gone wrong with this process. Start again.