@Override
    public Suggestions getSuggestions(final FetchSuggestionsRequest request) {
        return securityContext.secureResult(() -> {
            if (ExplorerFields.TAG.getFldName().equals(request.getField().getFldName())) {
                final Set<String> tags = getTags();
                return new Suggestions(new ArrayList<>(tags), false);
            } else {
                throw new RuntimeException(LogUtil.message("Unexpected field " + request.getField().getFldName()));
            }
        });
    }
Create a map of folders and their child items.
stroom-explorer/stroom-explorer-impl/src/main/java/stroom/explorer/impl/ExplorerServiceImpl.java