Just posting an update to my original question:
To clarify, my data dictionary is configured to not allow direct access from the base work space, for a variety of reasons.
As to using data from this dictionary to generate test iterations - I do this to avoid manual update to the test iterations if the data in the dictionary changes, as this data is used by multiple modules.
The answer on how to use this data is loading it into the base workspace at test run time.
Data is stored in "dictionary.sldd" under the "transitions" object. I pass this to my nested loop under the variable "Table"
% Open the dictionary object
DictObj = Simulink.data.dictionary.open('dictionary.sldd'); %open the dictionary object%
% Retrieve the section of the dictionary containing the data
SectObj = getSection(DictObj,'Design Data');
% Retrieve the data I care about
Entry = getEntry(SectObj,'transitions');
% Store the Entire entry
temp = getValue(Entry);
% Store the Value of the entry for generation of test iterations
Table = t.Value;
Hope this is helpful to someone else!