In a cyclic group, you can change the dimension of a chart following a specifi order when you left-click on the cycle button.
Field A - > Field B -> Field C -> Field A -> Etc
Or you can right click the icon and select any of the available dimensions.
On the other hand, in a drill down group, you follow a specific path when you select only one value of a given dimension.
If you have the dimension A -> B ->C in a drill down group, you can oly move to the dimension B after you have only one value in dimension A and move to dimension C after selecting only one value in dimension B
I'd say that the cyclic groups are move flexible but drill downs call be really helpful sometimes.
Hope this helps,
QlikView charts support flexible feature called variable groups. Groups are
lists of variables that are defined as cyclic or drill-down. These groups can flow
naturally, e.g., Year, Quarter, Month, Day, or mix any type of variables, e.g., Year,
Customer, Product. When a group is used as the variable specification in a chart, the
chart gains new functionality depending on the type of group used.
Drill-down groups specify variables that display sequentially as you drill-down in the
chart. When only a single value (one bar, one slice, or one point, depending on the
chart type) is available to be displayed in the chart, QlikView automatically drills down
to the next variable level. For example, a bar chart could be displayed showing total
sales for 12 months. When a single month's bar is selected, the chart can automatically
drill down to display sales for the 4 weeks in that month. When a single week is
selected, the sales for the 7 days of the week are displayed. When a single day is
selected, the sales for the individual customers could be displayed.
Alternatively, groups can be defined as cyclic instead of drill-down. When a cyclic
group is specified as the variable in a chart, a cycle button is automatically affixed to the
chart. When the cycle button is pressed, the chart displays the next variable in the
group. Alternatively, the user can right-click on the button to see a list of variables or
expressions in the cycle and move directly to any one. In the example above, the chart
would still start out displaying total sales for 12 months. When the cycle button is
pressed, the chart would change to show the sales for all 52 weeks of the 12 months (or
any months that were selected.) The chart would cycle through each of the variables
with each press of the cycle button.
Hope it will be helpful check..