If you are wondering how you can assign tags for dynamic limits in a Numeric Object, take note of the "Usage..." note in the Object Properties window.
The Numeric Object uses the tag assigned in the object properties as the Device Low limit, and uses the next sequential address as the Device High limit.
For example, If you assign LW-0 in the object properties, LW-0 will be the device low limit and LW-1 will be the device high limit.
If you want to use PLC tags as the device dynamic limits, then the tags must be sequential, such as elements of an array.
If the tags you want to use are not sequential, then you must use data transfer objects or macros to move the values from those tags into sequential local memory addresses on the HMI to use in the object properties.