If you are using probability scores, then it is very simple per the proportional draw assumption of the logit equation (which we've assumed and used to estimate scores and get you to the point you are) to allocate the share of choice across respondents for a subset of the items.
The first step is to assume a consideration set of 2 or more items. So, let's assume a consideration set of 3 items: items A, B, and C for illustration. Let's also assume the probability-scaled scores are 10, 15, and 25 for A, B, and C, respectively for respondent #1.
For respondent #1, the likelihood of choice would simply be proportional to the scores, made to sum to 100, or: 20%, 30%, and 50%.
Repeat this for all respondents and average the percentages across respondents.